"The fool hath said in his heart, there is no God. Corrupt are they, and have done abominable iniquity: there is none that doeth good." KJV
Man would rather believe in a lie, than to believe in the truth of God, therefore he denies God and becomes a fool.
If man does not believe in God then ultimately he becomes a persecutor of others. Survival of the fittest lends itself to kill others for the sake of their own survival.
Salvation is our only hope, no God leads to corruption, and a fatal life and then destruction.
Man finds his salvation and hope in God, in this alone is his rejoicing.